Upgrade did not go as asked for

I did an upgrade on two cellphone contracts from Cell C in November 2016. The guy I spoke to for the upgrade made my one contract WITHOUT my knowledge the data unlimited while there was only limited data. I only found that out when my account became sky high. I queried this every week and nobody could give me any feed back but that it's there problem they need to credit me --- but nothing happened. The disconnected my line and still no feedback. I have a ref number but still till this day the issue was not cleared. I am handed over to an attorney that I am not willing to pay since I have phoned Cell C every week for feedback. I want my name cleared and am not willing to pay even for the phones because my line was disconnected and since I begged them weakly for answers and nobody came back with answers and only handed me over.